1. Field of the Invention
This invention relates generally to hay harvesting and storage. More particularly, this invention relates to machinery for picking up large hay bales from the field, for transporting the bales to a storage area, and for unloading the bales there in a compact, secure stack.
2. Related Art.
To obtain the maximum production from a field of hay, each crop of hay must be promptly cut, baled and removed from the field. The more quickly hay can be cut and removed, the more quickly a successive crop of hay can be cultivated.
The harvesting of hay involves three main tasks: cutting the hay; baling the hay; and removing and storing the baled hay in stacks. Although originally manual tasks, nowadays these tasks to a great extent have been mechanized. Of these three tasks, the removing and stacking of the hay bales has heretofore been the most cumbersome.
The difficulties involved in removing and stacking hay bales are to a great extent dependant on the size and quantity of the individual bales produced by the specific hay baler that is used. Until recently, hay balers have come in three common sizes, producing the following sizes of bales: (1) 14" by 16" by 3 or 4 feet long; (2) 16" by 18" by 3 or 4 feet long; and (3) 16" by 24" by 4 feet long. These three sizes, collectively, fall into the category of "small bales". More recently, balers capable of producing bales 8 feet in length and having cross sections of 2 by 3 feet, 3 by 4 feet, or 4 by 4 feet, known as "big bales", have been produced. The larger bales mean less time is spent gathering, stacking and moving the bales. The primary factor limiting the use of "big bale" balers is the lack of effective machines designed to pick up, transport, stack and retrieve the big bales.
The most common prior art method for moving big bales from the field to a storage area is to use a tractor with a front end loader for loading the bales on a flatbed truck or trailer. Such a method is time consuming and requires at least two operators, i.e., one for each piece of equipment.
U.S. Pat. No. 4, 634,336 (Pearce) discloses a front-end bale loader with a platform carrying a pair of pivoted tines, which tines extend along the ground to engage beneath a bale. The tines may be rotated up to lift the bale off the ground, and the platform lifted and rotated to lift, and then discharge the bale.
U.S. Pat. No. 4,971,504 (Klompien) also discloses a front-end bale loader, but with a folding loading cradle pivotally connected to the front of the loader frame.
U.S. Pat. No. 5,397,208 (Siebenga) discloses a front-end bale loader which clamps bales between pick-up arms on the sides of a loading platform. Then, the loading platform pivots to lift the bales onto a downwardly and rearwardly inclined accumulating platform for storing the bales. One or two bales may be lifted at a time.
International Publication No. WO/86/07234 (Nygard et al.) also discloses a front-end bale loader which lifts the bales with a lift fork. This device may also load one or two bales at a time.